Instantaneous Power #8211; Instantaneous power is the power measured at a given instant in time. Suppose in a circuit V = V<sub>0</sub>sin ⍵t and I = I<sub>0</sub> sin(⍵t + ɸ), then P<sub>inst</sub> = VI = V<sub>0</sub> I<sub>0</sub> sin(⍵t + ɸ)